Other facts from our historical weather data: Which is the warmest month in Isleornsay? July has an average maximum temperature of 17°C (63°F) and is the warmest month of the year. Which is the coldest month in Isleornsay? The coldest month is February with an average maximum temperature of 8°C (46°F). Which is the wettest month in Isleornsay? January tops the wettest month list with 256mm (10.1 in) of rainfall. Which is the driest month in Isleornsay? May is the driest month with 135mm (5.3 in) of precipitation. Which is the sunniest month in Isleornsay? May is the sunniest month with an average of 197 hours of sunshine. No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.